The invention relates to an arrangement comprising at least one hydrostatic transmission, in which a hydrostatic unit functioning as a pump is hydraulically connected to a hydrostatic unit functioning as a motor in order to transfer drive power.
DE 28 15 632 discloses a hydrostatic transmission comprising two hydrostatic units, which are connected via a common connection plate to form an assembly. In order to reduce emitted operating noises caused by on-going compressions and decompressions of the hydraulic medium within the hydrostatic units (axial piston machines), it is proposed in DE 28 15 632 to mechanically decouple the assembly from an outer housing of the transmission by means of an elastic bearing.
In addition, reference is made to EP 2 503 190, which in order to reduce operating noises of a hydromechanical transmission arrangement, it is disclosed that the hydrostatic transmission part of the hydromechanical transmission arrangement is resiliently mounted relative to the transmission housing by damping elements.
Agricultural vehicles such as tractors, for example, increasingly comprise transmissions having a continuously variable transmission as part of the drive train. In terms of design, such transmissions having a continuously variable transmission (CVT) typically comprise, inter alia, a hydrostatic transmission having two hydrostatic units, which are hydraulically connected to one another. One of the units functions as a pump and the other unit functions as a motor. Given that at least one of the units has a variable hydraulic intake volume/pump capacity, the speed ratio between the shafts of the pump and the motor is steplessly adjusted.
The interaction of the hydrostatic transmission with a power-split mechanical transmission results, in combination, in a hydromechanical transmission arrangement, in which a transmission ratio between the input shaft and the output shaft is steplessly varied, at least within ranges. When the transmission ratio is changed, the split between the mechanically transmitted drive power and the hydraulically transmitted drive power also changes. Various designs of such transmission arrangements are known.
In practical application, it is shown that the above-described transmission arrangements, which comprise a hydrostatic transmission, very noticeably generate noise at least in certain operating situations, which is perceived at the least as being disturbing. Increased wear of affected components, which are caused to vibrate, may also occur in these operating situations. Depending on the design and dimensions of the transmission arrangement, it is not a sufficient solution to simply mechanically decouple the hydrostatic transmission in order to reduce operating noises at least in certain operating situations.